An economist examines the relationship between changes in short-term interest rates and long-term interest rates. He believes that changes in short-term rates are significant in explaining long-term interest rates. He estimates the model Dlong = β0 + β1 Dshort + ε , where Dlong is the change in the long-term interest rate (10-year Treasury bill) and Dshort is the change in the short-term interest rate (3-month Treasury bill). Monthly data from January 2006 through December 2010 were obtained from the St. Louis Federal Reserve's website. A portion of the regression results are shown below (n = 60):

Coefficients Standard Error t Stat p-value Lower 95%

Upper 95%

Intercept − 0.0038 0.0088 − 0.4273 0.6708 - 0.02 0.01 Dshort 0.0473 0.0168 2.8125 0.0067 0.01 0.08 Use a 5% significance level in order to determine whether there is a linear relationship between Dshort and Dlong.